West Nile virus spreading rapidly in Europe: cases in 12 countries
The number of West Nile virus infections in Europe has increased sharply. As of August 21, 625 locally acquired human cases have been reported in 12 countries, compared to 429 in nine countries on August 13. The virus has now been detected in 99 European regions, with 21 regions added to the list in the past week alone.
This is according to the latest data from the European Centre for Disease Prevention and Control (ECDC). Seasonal transmission of the virus is now approaching its peak period — usually the highest number of infections occurs in August and early September.
The highest number of cases has been recorded in Italy — 311. Greece has reported 157 infections, Spain — 63, North Macedonia — 37, Romania — 28, France — 17, and Serbia — six.
Two more cases have been reported in the Netherlands, and one each in Austria, Germany, Albania, and Kosovo. Overall, areas with confirmed local transmission of the virus have been identified in 12 European countries.
The virus has spread most widely in Italy, where 46 regional areas have been affected. In Greece there are 17 such areas, in Romania — 14, and in France — eight. Three areas with local transmission have been recorded in Spain, Serbia, and North Macedonia.
The situation has changed especially noticeably over the past week. As of August 13, the ECDC had reported 429 cases in nine countries. Thus, in less than ten days the number of reported infections has increased by almost 200, and the geographic spread has expanded to three more countries.
Virus spreading in new areas of Europe
The ECDC warns that West Nile virus continues to move into areas where local transmission had not previously been recorded. In 2026, six European regions reported local human infections for the first time in history.
Experts link the expanding geographic distribution of the disease to favorable conditions for mosquitoes and changing distribution of infection vectors. In Europe, West Nile virus is primarily transmitted by Culex mosquitoes, which are widespread across the continent.
For people traveling to or residing in Europe, the situation is particularly relevant in countries popular among Ukrainians — Italy, Greece, Spain, Germany, Austria, France, and Romania.
How West Nile virus manifests
The virus is transmitted to humans mainly through the bites of infected mosquitoes. About 80% of infections are asymptomatic. Around one in five infected individuals may develop West Nile fever, which is accompanied by headache, fever, weakness, muscle pain, vomiting, rash, or severe fatigue.
In less than 1% of cases, the infection can affect the nervous system and lead to severe neuroinvasive disease. Older adults and people with weakened immune systems are at increased risk of severe illness. There is currently no specific treatment or vaccine for humans against West Nile virus.
The ECDC recommends using repellents, wearing clothing that covers the body as much as possible, installing mosquito nets, and where possible reducing standing water around homes where mosquitoes can breed in areas where the virus is circulating.
European health authorities also use data on areas with virus transmission to ensure the safety of blood donations. Depending on the donor's place of residence, temporary deferrals or additional testing may be applied.
